Chronic disabling conditions have profound and pervasive effects on the lives of millions of Americans. Although rarely addressed, the need for health promotion continues to exist and may be accentuated in persons living with long-term, incurable conditions. The purpose of this five year competing continuation is to add depth to knowledge about health promotion in chronic disabling conditions by incorporation a longitudinal follow-up of the existing sample of rural and urban persons with multiple sclerosis (MS), integrating additional outcome measures. It will also expand knowledge of health promotion and quality of life among persons with chronic neurodegenerative conditions through validation of the explanatory model refined in the present study in a population of persons with a different chronic condition, post-polio syndrome. The specific aims are to (1) Conduct a longitudinal follow-up of persons in the current project to examine the effects of time and the trajectory of illness-related disability on a range of quality of life outcomes (perceived quality of life, employment, depression, and secondary disabilities); (2) Examine the influence of health promoting behaviors, barriers, and resources on individual change trajectories over multiple points in time, when controlling for the effects of illness-related disability; and (3) Validate and refine the explanatory model of health promotion and quality of life developed in the current study with an additional chronic disease population, persons with post-polio syndrome. A five year follow-up of the existing sample of persons with MS (N=759) is proposed; only 5% of the sample has been lost to follow-up at 2 years and 90% responded to a Time 2 questionnaire. A second sample of persons with post-polio (N=500) will be recruited. Instruments and data collection procedures refined in the present study will be incorporated in the continuation. Longitudinal data will be analyzed with hierarchical linear models (HLM) and event history analysis. Structural equation modeling (SEM) techniques will be used to validate and refine the model in the post-polio group. Information from this study will be used to design nursing interventions for persons with chronic neurodegenerative conditions.